Engines can be fitted with a turbocharger system to increase the performance of the engine. For multi-stage series turbocharger systems, a trade-off exists between the maximum power that can be achieved from the engine at high engine speed and the maximum torque that can be achieved in the mid speed range. Such a problem is commonly known as “mid-speed torque dip”.
Where a low pressure (LP) stage of the turbocharger system is configured to deliver a high flow capacity, a high power output can be achieved at the expense of the torque dip in the mid-speed range. Conversely, where the LP stage of the turbocharger system is configured to deliver a low flow capacity, the torque dip can be eliminated but at the expense of maximum power output.